The use of high frequencies in fill level measuring provides many advantages. For example, in this way the components of sensors may be kept smaller.
In fill level measuring in the high-frequency range there are three different frequency bands. Firstly the so-called C-band, which ranges from 4 to 8 GHz; the K-band, which ranges from 18 to 27 GHz; and the so-called W-band, which approximately ranges from 75 to 110 GHz.
When compared to other frequency bands, the high frequencies of the W-band may require particular design techniques in the construction of the HF module, which design techniques may not be necessary at frequencies in the C-band and K-band.
While in the electronics modules of fill-level radar devices (so-called radar front-ends), which operate in the C-band or in the K-band, exclusively housed high-frequency components (HF components) may be used, in the W-band so far, generally speaking, only non-housed components may have been used. The reason for this is that in the case of the high frequencies in the W-band the parasitic effects of a component housing may very considerably impede the function of the high-frequency components and also the functions of the monolithic microwave integrated circuits (MMICs).